Treatment of wool



Patented Jan. 16, 1945 TREATMENT OF wooL I Archibald John Hall andFrederick Charles Wood,

Manchester, England, assignors to Tootal Broadhurst Lee Company Limited,Manchester, England, a British company No Drawing. Application October24, 1940, Serial No. 362,694. In Great Britain October 30, 1939 14Claims.

This invention is primarily concerned with the treatment of wool, thoughit may also be applied to the treatment of other materials, especiallytextile materials. The reagent used for the purpose is believed to benovel. I

The invention is thus particularly concerned with the treatment, inwhole or in part, of materials consisting wholly or partly of wool'toreduce or substantially eliminate their usual tendency to felt whenwashed in aqueous liquors. The wool may be in the form of loose fibresor in a manufactured form such as yarn and fabric which may havereceived some treatment such as scouring, bleaching, dyeing, hotpressing'and milling.

The term wool" includes all animal fibres which are capable of beingfelted.

In describing this invention, the term felt" is to be understood torefer to that property of ordinary wool which causes the individualfibres to close upon each other in washing, or other treatment inaqueous liquor in which the wool material is repeatedly squeezed andrubbed, so that the wool material becomes denser and more compact. Thisproperty of felting is responsible for the shrinkage which wool yarnsand fabrics suffer when washed, so that such materials may be made'lessshrinkable by treating them according to this invention.

Materials containing wool which have alreadybeen partially felted may beprevented from further felting by the process herein described.

According to the present invention, the wool or other material istreated with a reagent containing little or no water comprising (a) analkallne substance; (b) an organic solvent for (a) and (c) an organicliquid which is a non-solvent or poor solvent for (a) and miscible withthe solution of (a) in (b). Preferably the non-solvent is in largeexcess. After such treatment it is desirable to remove or otherwiserender innocuous unchanged alkali and medium and the decompositionproducts to an extent such that the wool will not deteriorate duringsubsequent storage.

The term alkaline substance is defined herein as a substance which inpresence of water, would give hydroxyl ions, and includes alkalies ororganic bases or substances producing or capable of producing an alkalior organic base, preferably of stronger basic nature than ammonia.

The preferred alkaline substances are those (of stronger basicnaturethan ammonia) which,

in the presence of a suitable amount of moisture may exert agelatinizing action on wool and may to some degree produce chemicalchanges or decomposition of the wool. Among. those found effective areorganic ammonium, sulphonium and iodonium hydroxides such asbenzyltrimethyl ammonium hydroxide; tertiary amine oxides; by-

' liquids which in absence of the alkaline substance would be chemicallyinert or relatively inert to wool or other material undergoingtreatment.

The organic solvent (which term includes a single liquid or a mixture ofliquids) is chosen with relation to the alkaline substance. Suitablesolvents may be found among the aliphatic alcohols especially thosecontaining three to eight carbon atoms, but also oleyl, stearyl,ricinoleyl, or aromatic alcohols such as benzyl alcohol or phenyl ethylalcohol, hydroaromatic alcohols such as cyclohexanol, amino alcohols orglycol vethers such as ethylene glycol, acetone, ethylacetoacetate,aniline, ethyl acetate or amyl acetate.

In treating wool, alcohols containing 3-8 carbon atoms are preferred ascompared with methyl or ethyl alcohol. Preferably the flash point of themixture of solvent and non-solvent is above 60 F'. (Abel test). Mixturesof white spirit of flash point 92 F. with only 2% of ethyl alcohol showa flash point of F. whereas the addition of 2% of n-butyl alcohol merelyreduces the flash point to 82 F.

The non-solvent or poor solvent (which term includes a single liquid ora mixture of liquids) is preferably a hydrocarbon such as a petroleumdistillate, e. g. paraffin, hexane, white spirit (a petroleum distillateof boiling range 150-260 C. and sp. g. 0.81), or petrol or chlorinatedhydrocarbon or an aromatic or hydroaromatic hydrocarbon such as tolueneo'r tetrahydronaphthalene, but other non-solvents and poor solvents suchas pyridine, ketones, ethers or esters or higher alcohols may be used.

These'non-solvents and poor solvents act as In certain cases the diluentmay consist of a good solvent for (a) suitably diluted with a nonsolventor poor solvent. The desirable property of a diluent to give a uniformtreatment is that it can be addedto and be perfectly miscible with asolution of the type (a) in (b) so as to yield a solution or uniformdispersion containing an amount of alkali capable of acting on the woolor other material to the extent desired.

We have found the reagents according to the invention are generally lessharmful to the wool as regards lowering its quality and are more efthemethyl, ethyl and butyl ethers of fective in reducing its felting powerthan solu--' tions of alkalies without diluents. Our reagents aresimilarly more satisfactory when they contain a higher proportion of thediluent and a. lower proportion of the solvent. We prefer to usereagents which contain the highest propor. tion ofdiluent consistentwith the alkali remain ing in solution. It is believed that the presenceof the diluent is beneficial. partly because, owing to its non-solventproperties, it tends to force the alkali from the solution onto thewool.

It is believed, although this does not limit this Invention in any way,that the action of the alkaline treatment is mainly confined to thesurface of such wool fibre, and that any substantial extension of thisaction to the interior of the ilbre adversely aflfects its quality. Theterm quality" is here to be understood to refer to a number ofproperties of the wool, such as tensile strength, softness of handle,colour and durability, which have to be taken into account in assessngthe value and usefulness of a wool material. In general, the quality isreduced if the wool loses :1 weight and is made weaken-harsher, yellowerand less durable.

It has been observed that under certain condi- ;ions of carrying outthis invention, the wool may act only have its felting power decreased,but it nay also suffer changes which reduce its original uality. It istherefore necessary to arrange coniitions of treatment which willproduce the re mired decrease of felting power accompanied of reagentscontaining appreciable amoimts of 2y any other change in the quality ofthe wool which is permissible or desired for the purpose in dew.

In carrying out this invention, adequate conrol-of the results obtainedis possible because the :onditions of treatment of the wool may bevaried videly. It has been found that the quality and he decrease offelting power of the treated wool :an be controlled by varying:

1) The composition of the reagent as regards its content of one or moreof the alizalies and one or more of the solvents and poor ittention mustbe given to all these conditions f treatment of the wool in order toobtain the esult desired.

We prefer to use reagents which contain little r no water, but it isimportant to note that this ondition refers to the reagent and not tothe pol under treatment. Some water may be presnt arising from directaddition or its presence my be adventitious arising from difficulties ofbtaining completely water-free ingredients of ie reagent or preventingthe entrance of water uring the preparation of --the reagent. Many of iereagents used, particularly those containing large proportion ofahydrocarbon or other oranic solvent not containing a hydroxyl groupDH), are almost immiscible with water. The :agents used in thisinvention are preferably lose which contain not more than about 2% ofater (by volume) but they may contain quanties up to the limit of itssolubility in the rerent.

water is generally harmful in that the quality of the wool is lowered.This may be corrected to a certain extent by decreasing the time ofaction or otherwise adjusting the conditions of the treatment. Woolharmed by such treatment usually has a pronounced yellow colour whichmay be accompanied by an impoverished handle, loss of weight andappearance.

The effect on the resultingdecrease of felting power of the woolproduced by adding water to the reagent varies considerably according tothe composition of the reagent.

The moisture content of the wool when treated with the reagentinfluences both the reduction or felting power and the lowering ofquality of the wool so that ,this moisture content may be varied widelyaccording to the results which aredesired. In general, wetting of thewool with waterbefore treatment promotes a lowering of the quality ofthe treated wool. But to some extent, this harmful action may becounteracted by reducing the duration of the treatment, and otherwiseadjusting the conditions of the treatment.v But even when theseadjustments are made, the treated wool is generally less satisfactorythan when it is treated in an air-dry state. On the other hand, woolwhich is completely free from moisture is less reactive to the alkalitreatment.

We have found that wool can be made nearly non-felting withoutappreciable loss of by treating it with the reagent when the woolcontains 12-18% of water, and these conditions i are preferred.

Generally, the action of this alkali-treatment on wool with a givenmoisture content increases withincrease of temperature and with increaseof *duration of treatment. At temperatures below ods of carrying out theinvention involving the use of reagents having constituents which aregaseous at ordinary temperature and pressure (e. g. butadiene) increasedpressure is desirable.

These volatile constituents may then be largely removed at the requiredtime merely by releasing the pressure.

Conditions may also be arranged so that the her in which such conditionssuch as composition of the reagent, temperature and duration oftreatment, and the moisture content of the wool at the time of itstreatment, effect the results obtained, it will be understood that thesecondn has been observed that the acti n on W001 tions can be much variedand that similar results can be obtained bydifferent sets of conditions.

For the production of any particular dzrzired result, it may benecessary to make a few simple trials to ascertain the most suitableconditions of treatment to be used.

The treatment of wool with these reagents may quality,

produced. Thus the wool may be led through the reagent, then squeezed toremove loosely adhering solution, and allowed to lie at room temperaturefor a sufiicient period to obtain the result desired.

Alternatively, and this is one of the preferred methods, the wool may besteeped in the reagent until the desired effect is obtained, and thenexcess liquor removed by any suitable method such as centrifuging. It isfound that a weaker alkalisolution may be used when the wool is treatedso that it remains in contact for a considerable period with arelatively large volume of it than when the wool is rapidly impregnatedwith a relatively small volume of the liquor and then allowed to lie atroom temperature for completion of the action, but the increase ofalkali concentration required in the last named impregnation method maybe reduced by allowing the impregnated wool to lie at a relatively hightemperature, say 50 to 100 C. or even higher.

After the wool has remained in contact with the alkali solution undersuitable conditions to obtain the desired reduction of its feltingpower, the alkali inthe wool should be removed by thorough washing withwater which may be followed by treatment with an acid or by direct acidtreatment followed by washing. In the former case care must be taken toavoid damage to the wool which may result from allowing it to be incontact with a high concentration of aqueous alkali. Alternatively thebase in the wool is combined with substances so as to form products inor on the wool which have useful softening, lubricating or otherefiects; high molecular weight acids such as oleic acid or oleylhydrogen sulphate may be used for this purpose.

Neutralisation in the absence of water may be carried out by treatingthe alkaline wool with acid gases or vapour or with a'solution of anacid in an organic solvent. v

Although it is believed that this invention will be largely used for theall-over treatment oi materials consisting entirely or in part of woolfor the purpose of rendering them non-felting, it is to be understoodthat it may also be used for treating such materials in selected partsor areas for the production of special effects. For example, the reagentmay be applied to a woven wool fabric by textile printing methods orotherwise'to produce a striped or other pattern so that when the fabricis afterwards washed it will felt to a less degree in the treated parts.a

This invention is especially useful for the treatment pf wool mixed withfibres such as those of cotton and viscose rayon, since the alkali hasno adverse action on these fibres. Other fibres which may be presentwith the wool are for example nylon, linen, rubber threads as forinstance those used in elastic belts and garters of woollen goods, etc.

For determination of shrinkage in washing in these examples thefollowing method may be used.

A portion of the fabric is first steeped in water and then dried freefrom tension. A square of cm. side is then marked on this relaxedfabric. The fabric is then washed (together with other fabrics forcomparison when so desired) by hand with repeated squeezing in a /2%soap solution at SID-40 C. for a desired period, say 10 mins. The fabricis then rinsed in water, and dried free from tension. The marked squareis then measured and the resulting contraction of area calculated andconsidered to be the area shrinkage.

The following examples illustrate the treatment of wool:

Two dozen pairs of men's wool socks weighing 8% lbs. were first scouredand lightly milled in a warm soap liquor, washed, dried, conditioned soas to contain 12.5% of moisture, and then steeped for 1 hour in 6.!gallons (British gallons) of a liquor initially at 17% C. and preparedby adding 6 gallons of kerosene to 0.7 gallon of a solution of causticsoda in normal butyl alcohol having a composition of 6 lbs, of causticsoda per 10 gallons 0! n-butyl alcohol. The socks were then withdrawn,centrifuged so that they contained not more than 0.15 gallon 01 residualliquor, and plunged into 8 gallons 01 cold water containing 0.2 gallonof sulphuric acid (sp. gr. 1.8) to neutralise the alkali in the wool.Thereafter the socks wer thoroughly washed and dried when they werefound to have considerable resistance to felting.

It was noted that no rise in temperature oi the reagent occurred duringthe treatment of the socks.

. Example I! Solutions of caustic soda were made in normal butylalcohol, glycol monoethyl ether and absolute ethyl alcohol, ofconcentrations shown in the table, column 1. The use of these solutionsin alcohols is part of our Ser. No. 362,695, filed 0ctober 2d, lied.

Col- Column 1 Column 2 Column 8 ohm Area Composition oi solution Stocksolution used in treatment oi x2 3 5253 3g the wool washing 1 volumestock solution For Normal butyl alcoplus cent hol-caustlc soda. 9volumes butyl alcohol. 7 A 6.4 g. NaOH in Y cc. solution. 1 volume stocksolution P 0.3 X 9 volumes white spirit. A

1 volume stock solution Glvcol monoethyl plus a 25 B other-caustic 22vols. glycol monoa soda. 14g.NeOH ethyl ether. '5 in 100 cc. solution. 1volume stock solution 8 p 5 1.6 Y 22 vols. white spirit. :1 O 1 volumestock solution E Absolute ethyl alglue as 16.6 C

cohol-caustic 9 vols. et yl alcohol. t? it it E s cc.- somflon- 1 volumesolution 12. 6 Z

9 vols. w ite spirit.

Untreated fabric 34 U From these stock solution more dilute solutionswere made by dilution with the alcohols concerned, or, according to thepresent invention, with white spirit, as shown in column 2. Samples 'ofwool fabric conditioned over saturated brine were immersed in thesesolutions (column 2) for one hour at 20 C. The samples were thenremoved, centrlfuged, plunged into acidulated ficial effects in respectof resistance to shrinkage and felting'which are obtained when theimpregnating solution contains a preponderating amount of thenon-solvent for the alkali (e. g. white spirit) and particularly whenthe higher alcohols are used as solvents for the caustic alkali.

Example III 0.5 cc. water was added to 10 cos. of a caustic soda-butyl.alcohol solution (containing '7 gm. NaOH in 100 ccs. butyl alcohol) andthen this was made up to 100 ccs. by addition of white spirit.

A knitted wool fabric was immersed in this at ordinary temperature for15 minutes. It was then taken out and mangled, plunged into dilute acidand well washed successively in water and soap solutions.

A comparative test with an untreated fabric showed that on vigorouswashing and rubbing the blank sample shrank 41.5% in area while thetreated only shrank 12.5% in area. The treated.

sample had also resisted felting.

Example IV A sample of. knitted woolen fabric was completely dried in ahot oven and then put in a closed vesse1 containing methyl alcohol andits vapour. After some hours it was plunged into the following ternarymixture at 45 0.: one volume of caustic soda+butyl alcohol (6 g. NaOHper 100 ccs. mix-.

ture), diluted with 9- volumes of white spirit. After 2 minutesimmersion the Wool was taken out, squeezed between rollers and thealkali im mediately neutralized with aqueous acid and the sample washedsuccessively in water and soap solutions. A comparative washing test ofthis treated sample with an untreated sample showed reduced felting andshrinking properties.

Example V scoured knitted wool fabric containing rubber threads coveredwith cotton was steeped for one hour in a liquor initially at, 16 C. andprepared by diluting 10 cc. of a 6% solution of caustic soda in n-butylalcohol with 90 cc. of white spirit. The fabric was then centrifuged,acidified with dilute sulphuric acid, thoroughly washed and dried. Theresulting fabric had excellent resistance to felting and the rubberthreads were not appreciably affected by the treatment.

The following examples illustrate variations in alkaline substance: I

Example VI A mixture of normal butyl alcohol and white area shrinkagesfor the treated and untreated fabrics were and 44% respectively.

Example VII 5 grams 'of air dry knitted wool fabric were immersed forhour in a liquor at 30-40 C. consisting of 30 ccs. of ethylene diamine,2.5 ccs. of

white spirit and 15 cos. of butyl alcohol. The fabric was then mangled,acidified with dilute hydrochloric acid, washed and dried, when it wasfound to havevery good resistance to felting.

Example VIII A wool fabric was thoroughly wetted with waterand-squeezed'ofi by passing through the nipping rollers of a mangleadjusted so that the fabric after mangling contained its own weight ofwater.

The fabric was then immersed in a solution containing '70 cc. of whitespirit and 0.9 g. of metallic sodium dissolved in 30 cc. butyl alcohol.

After 3 mins. the material was mangled so as to remove excess liquor,washed, soured with acid to'neutralise any excess alkali and washed insoap.

The fabric had a much reduced tendency to felt during washing with warmsoap solution after its treatment.

Similar results were obtained by using the same reagent for a longerperiod of time to treat wool fabrics containing 14% and 6% of moisturerespectively.

Example IX A solution of caustic soda was made in normal butyl alcoholso as to contain 6 gm. NaOI-I in 100 cc. solution.

This was then diluted with five times its volume of White spirit so asto contain 1 gm. NaOH in 100 cc. mixture; CO2 gas was blown through 100cc. of this solution until it was saturated. A gelatinous emulsion wasformed in this process, to which another 100 ccs. of the originaluncarbonated solution (-1 gram NaOI-I in 100 cc. butyl alcohol+whitespirit) was added and the resulting dispersion thoroughly shaken.

A number of samples of conditioned knitted wool (conditioned oversaturated brine) were immersed in this dispersionat temperaturesmaintained at 20 C., 40 C., and C., for varying periods of time from 2hours to 16 hours at 20 0.; 15 mins. to 4 hours at 40 C. and 1 and 2hours at 60 C.

After the prescribed periods of time had elapsed the wool samples werecentrifuged to remove excess liquor and plunged into acidulated water,rinsed in dilute ammonia, rinsed again and finally soaped lightly toremove solvent, rinsed and dried.

All those samples treated at the same temperature, together with acontrol untreated sample, were subjected to a drastic washing andfelting treatmentin soap solution with mechanical action.

All the treated samples showed remarkable resistance to shrinking andfelting as compared with the untreated sample. One set of area shrinkagefigures obtained are given in the following table:

Time of immersion (in ou t- Percent 2 38 to felting.

- then taken out, squeezed through rollers and plunged into dilute acidand finished in the usual way. It was found to possess increasedresistance Example XI An amount of sodamide was reacted with excess ofaniline in a stream of coal gas passing through the apparatus so as toproduce a concentration of sodiophenylamine equivalent to 0.7 g. NaOHper 100 ccs. mixture. This solution of sodiophenylamine in aniline wasdiluted 7-fold with dichlorethylene so as to give a mixtur ofsodiophenylamine in aniline and dichlorethylene. The concentration ofsodiophenylamine in this diluted solution was equivalent to0.1 gm. NaOHper 100 ccs. mixture. A piece of knitted woollen fabric was immersed inthissolution at room temperature for 24 hours. It was then mangled andplunged into dilute HCl and well washed in water and given a lightsoapin followed by drying. This treated sample showed-a reduced tendencyto felt and shrink.

, Example XII 1 A solution of caustic potash was made in absoluteethanol (ethyl alcohol) containing 6 g. of

XOR in 100 cc. solution. 10 cos. of this solution was diluted with 90cos. of white spiritgiving a solution containing 0.6 g. KOH in 100 '00s.A sample of knitted woollen fabric weighing 7 grams was immersed in thissolution for 1 hour at 18 C. It was then removed, mangled, and plungedinto dilute acid. It was then washed in-water, washed again in soapsolution and finally in water. The sample was dried and showed a muchincreased resistance to felting when washed together with an untreatedsample.

The following examples illustrate variations in solvent (see alsoExamples m and Example XIII A solution of 5 gm. sodium peroxide wascautiously made in 100 cc. butyl alcohol. When no further oxygen cameofl, 85 ccs. of this was di-' luted to 600 cc. with white spirit. Theconcentration of NaOI-lin the butyl alcohol-l-white spirit mixture wasthus about 0.7 gm. per 100 cc.

118 gm. of a woven wool fabric was immersed in the solution till it waswetted with the liquid and then run through squeezing rollers. Theweight of the impregnated cloth was 215 gm.- corresponding with a liquorcontent of 82%. After 20 minutes the fabric was passed through wateranda soap bath, washed and soured and finall dried. The fabric had muchreduced felting power.

Example XIV All fasa atsvs 5 If wool is treated with the above mixturefor one hour at ordinary room temperature a greater decrease of thefelting-power of the wool is obtained than when a binary mixture of NaOHand methyl alcohol is used under similar conditions.

EzrampleXV Solid caustic soda was warmed with ricinoleyl alcohol and 10ccs. of the warm liquid poured of! and mixed with a mixture of 10 cos.of ricinoleyl alcohol, 20 ccs. of dichlorethylene and 70 cos. of whitespirit, thereby giving 110 cos. of a potentially alkaline solutionequivalent to 0.4 g. NaOH- per ccs. solution. Air-dry wool samples were.

immersed in suitable volumes of this solution for l-d hours, squeezed,then acidified, washed free from solvent, and dried. The samples showedresistance to felting and shrinking. Y

' Example XVI A solution of caustic soda was made in the coldinphenylethyl alcohol (CsHr.CH2.CH2-OH) with excess of solid NaOH presentand the liquids poured off. This was diluted with white spirit and thefinal analysis showed it contained 0.34 g.

of NaOH per 100 cos. of mixture. Air-dried knitted woollen fabric waimmersed in this solution for 24 hours at ordinary temperature,squeezed, neutralized, washed and dried. A washing test showed thetreated sample to be resistant to felting and shrinking.

The following examples illustrate a variation in non-solvent and poorsolvent (see also Examples m, XIV, XV)

Example XVII A solution of caustic soda. in n-butyl alcohol (6 gramsNaOH in 100 ccs.) was diluted with 9 times its volume of carbontetrachloride and conditioned wool fabric was then treated with thissolution (ratio liquor to cloth=8/l) for 1 hour at 20 C. The fabric wasthen acidified, washed and dried and then found to possess excellentresistance tofelting and shrinking.

Wool may also be treated to have its felting power reduced with liquorsprepared b treating gents include esters, ethers, fats, hydroxyliccompounds, and may if desired be in the form of moulded articles,sheets, tubes, fibers, yarns and fabrics made from these and thetreatment may becarried out so as to produce a partial modification orcomplete modification of the particular substance or material which isbeing subjected to the treatment.

The material to be treated may contain-a nonreactive part in addition toa reactive or partially reactive part or both, and hence a partial orcom-- plem separation of component parts may be facilitated.

In the case of 'a partial conversion of materials to other materialseither the unchanged portion or the portion which has undergoneconversion may if desired be simultaneousl or afterwards removed by wellknown processes.

Exampl XVIII Normal butyl alcohol was shaken in a machine,

with solid caustic soda till a solution-emulsion was obtained. This waspoured ofi from the solid caustic soda and analyzed.

The solution-emulsion was found to contain 15.4 gms. NaOH in 100 ccs.(88 gms.)

To 1%; litres of this solution-emulsion, 2.25 litres of normal butylalcohol was added giving 3.75 litres of a clear solution of caustic sodain butyl alcohol containing about 64 gm. NaOH per litre.

One litre of this solution was diluted to litres with white spirit." Aclear solution was obtained thus containing 6.4 gm. NaOH per litre.

This solution has the interesting property of giving a fine dispersioncontaining caustic soda when warmed, which redissolves on cooling. Thisproperty may be utilized in treating materials with the reagent.

The reagent may, for example, be used for the following purposes:

(1) The reduction of the acyl content of cellulose esters such ascellulose acetates, propionates, etc.- or hydrolization of otherderivatives of cellulose, e. g. cellulose fibres, which have been and.starch, and dried. The fabric was then treated as described in ExampleXIX whereby it became dyed only in the non-printed part to give a whitespot pattern on a blue or other coloured ground.

Example XXI One part of damp (not wet) plain bleached cotton fabric wasimmersed for one hour'at'room temperature in a solution consisting of0.2 part (4) The transformation of ethyl acetate into ethylacetoacetate.

(5) The cleaning of greasy metal and other materials, also the drycleaning of textiles.

(6) The removal of carbon dioxide from gases by bubbling through thereagent.

(7) The treatment of cotton, regenerated cellulose, or silk fibres toeffect a superficial swelling. This makes the fibres superficiallyreactive after which they may be subjected to other treatments.

This list is not exhaustive. The following examples illustrate some ofthese aspects of the invention.

Example XIX Example XX Cellulose acetate woven fabric was printed togive a spot pattern with a resist paste consisting of tartaric acidthickened with British gum ,ment is from 1-24 hours.

of caustic soda, 8 parts of butyl alcohol, and 92 parts of white spirit,and then mangled and immersed for five minutes at room temperature in asolution consisting of 5 parts of sulphuryl chloride in 100 parts ofwhite spirit. The fabric was then mangled and thoroughly washed withdilute aqueous ammonia, then washed with water, and dried. The resultingfabric had a more sheer appearance and was stiffer as though it had beenpartly parchmentized.

The products according to the invention diifer from non-felting woolprepared by treatment with chlorine or chlorine compounds in that they,

usually acquire a stiffer and fuller handle when wetted in slightlyalkaline liquor but that on drying they lose this increased stiffnessand fullness so as to regain their original handle. This char.-acteristic of the wet product is in marked contrast to the thinnerslippery handle of wool processed with chlorine or chlorine compounds.

In the specification, the term dispersions" includes solutions,suspensions or emulsions.

A preferred concentration of alkaline substance, is less than 1 gramNaOH (or an equivalent amount of another alkaline substance) andpreferably from about 0.2 to 0.7 gram NaOH (or an equivalent amount ofanother alkaline substance) per 100 cc. dispersion. A preferred time oftreat- A preferred temperature of treatment is l0-50 or more usually12-30 C. The diluent preferably forms a major proportion of thedispersion, e. g. over and often over 75% by volume.

We declare that what we claim is:

1. A process of reducing the tendency of wool to felt, which comprisestreating the wool with a reagent containing not more than substantiallytwo percent of water and consisting essentially of an alkaline substancehaving a stronger basic nature than ammonia, a liquid organic solventfor the alkaline substance, and an organic diluent liquid which is apoor solvent for the alkaline substance but is miscible with thesolution of the alkaline substance in said organic solvent to give astable dispersion.

2. A process of reducing the tendency of wool to felt, which comprisestreating the wool with a reagent consisting essentially of an alkalinesubstance having a stronger basic nature than ammonia and dispersed in amajor proportion of a diluent hydrocarbon by the aid of a minorproportion of analcoholic solvent of said are line substance, saidsolvent being miscible with the hydrocarbon, the maximum content ofwater in said reagent being not more thansubstantially 2 percent.

3. A process of reducing the tendency of wool to felt, which comprisestreating the wool with a reagent containing not more than substantiallytwo percent of water and consisting essentially of a caustic alkalihavinga stronger basic nature than ammonia, an alcohol effective as asolvent for the alkali, and a petroleum distillate which is a poorsolvent [or the alkali but is miscible with the alcohol solution of thealkali to give a stable dispersion.

a. A process of reducing the tendency of wool to felt, which comprisestreating the wool with a reagent containing not more than substantiallytwo percent of water and consisting essentially of caustic soda, butylalcohol, and a volatile petroleum distillate which is a poor solvent forthe alkali but is miscible with the solution of the alkali substance insaid butyl alcohol to give a dispersion.

5. A process of reducing the tendency of wool to felt, which comprisestreating the wool with a reagent consisting essentially of an alkalinesubstance having a stronger basic nature than ammonia, a liquid organicsolvent for the alkaline substance, and an organic liquid which is apoor solvent for the alkaline substance but is miscible with thesolution of the alkaline substance in said organic solvent to give adispersion, said reagent containing not more than substantially 2percent of water; removing the treated wool from the reagent, andneutralizing the residual alkaline substance present in the wool in thesubstantial absence of water.

6. A process of reducing the tendency of wool to felt, which comprisestreating the wool for 1 to 20 hours at a temperature of to 50 degrees C.with a reagent containing not more than substantially two percent ofwater and consisting essentially of an alkaline substance having astronger basic nature than ammonia and dispersed in a liquid comprisingat least '75 percent of an organic diluent liquid which is a poorsolvent of the alkaline substance by the aid of not exceeding 25 percentof an alcoholic solvent of said alkaline substance, said alcoholicsolvent being miscible with the said poor solvent to provide a stabledispersion of the alkali substance, said alkaline substance beingpresent in quantity for providing an alkaline concentration of 0.05 to 1gram of alkali expressed as sodium hydroxide per 100 cc. of reagent.

'7. A process of reducing th tendency of wool to felt, which comprisestreating the wool with a reagent containing not more than substantiallytwo percent of water and consisting essentially .of an alkalinesubstance having a stronger basic nature than ammonia, an alcoholeffective as a solvent for the alkaline substance, and an organicdiluent liquid which is a poor solvent for the alkaline substance but ismiscible with the alcohol solution of the alkaline substance to give adispersion.

9. A process of-reducing the tendency of wool to felt, which comprisestreating the wool with a reagent containing not more than substantiallytwo percent of water and consisting essentially of an alkaline substancehaving a stronger basic nature than ammonia, a monohydric alcohol con--taining 3 to 8 carbon atoms and efiective as a solvent for the alkalinesubstance, and an organic diluent liquid which is a poor solvent for thealkali but is miscible with the solution of the alkaline substance insaid monohydric alcohol to give a dispersion.

10. A process of reducing the tendency of wool to felt, which comprisestreating the wool containing 12 to 18 percent of water for substantiallyone hour at a temperature of substantially 12 to 30 degrees C. with areagent containing not more than substantially two percent of water andconsisting essentially of caustic soda, n-butyl alcohol, and petroleumdistillate having a boiling range of 150-260 degrees C., the causticsoda being present in the proportion of 0.2 to 0.7 gram per cc. ofreagent, and the petroleum distillate forming at least '75 percent ofthe reagent.

11. A process as in claim 1 in which the treatment is applied to amaterial containing wool and other fibres.

12. Wool treated by the process of claim 1, and characterized in havingthe interior of the fibre substantially unchanged and possessing thetensile strength, softness of handle, durability and to felt, whichcomprises treating the wool with a reagent containing not more thansubstantially two percent of water and consisting essentially of acaustic alkali having a stronger basic nature than ammonia dispersed ina major proportion of a volatile hydrocarbon liquid which is a poorsolvent for th alkaline substance by the aid of a minor proportion of analcohol in which at least a part of said substance is dissolved, saidhydrocarbon liquid being miscible with the solution of the alkalinesubstance in said organic solvent to give a dispersion.

14. .A process of reducing the tendency of wool to felt, which comprisestreating the wool with a reagent containing not more than substantiallytwo percent of water and consisting essentially of caustic sodadispersed in a major proportion of a volatile hydrocarbon liquid whichis a poor solvent for the caustic soda by the aid of a minor proportionof an alcohol in which at least a part of said caustic soda isdissolved, said hydrocarbon liquid being miscible with the solution ofcaustic soda in said alcohol to give a dispersion.

ARCHIBALD JOHN HALL. FREDERICK CHARLES WOOD.

